Most of the time cleaning the IAC is only a temporary fix usually it will work better for about a day or two then give you trouble again. It doesnt hurt to try though. As far as the gasket goes they usually stay in one piece and you can use it again. But you may want to go ahead and price the part and save a little time. When I did clean them I used a very small brush and sprayed a lot of pb blaster in the valve as I cleaned it.

 

ok... well still haven't gotten to the IAC... but am pretty irritated now. I've been out on the freeway driving... everytime I let off the gas as highway speed 65+ the overdrive kicks off... you can feel it. I don't remember doing this before I disconnected the battery... but I've only had the truck a couple weeks so still feeling it out. I know before I did anything to it... it would sometimes kick from 2nd to 3rd gear.... but not always and it does that now too... sometimes. Seems like it will do it more when it is warm than cold, but not always the case. I checked the trans fluid and it looks ok, kind of smells funky, but not burnt. I looked through the previous owners records, (he marked everthing he did to it) and the trans was serviced... pan, filter, full fluid change about 20,000 miles ago, but he didn't drive it much and the service was almost 4 years ago...
Is there any speed sensor, trans sensor or vac line that I should check for the shifting issue? Might the pcm figure it out... I haven't driven it but maybe 15 miles since I reset it... but even if the overdrive works out, it still has the kick from 2 to 3...or might that all be connected. Before the reset, if I would cruise 35 to 45, it would kind of seem like the truck didn't know what gear it wanted, I could let off the gas just a little and it would drop down and just a little more and it would kick up. I don't know much about transmissions... so any info would be great... I don't think its the actual trans. I'm thinking sensor.

 

forgot to say... still no codes, or check engine light...
Was doing some reading on here... does a TPS sound like it could cause it?

 

On your truck there should be a trans control module on the side of the trans. But transmissions are not really my expertise. Maybe there is a transmission guy on here. I would start a new thread titled auto trans help and see if someone chimes in. But if you have a junkyard close by you may want to try another control module if its not too costly.

 

Hi, Well I've been able to drive the truck a bit more. The overdrive dropout at highway speed, I think has gone away... didn't notice it today. Still got the little kick going into 3rd, sometimes. I tested the tps... it does have one bad spot on it. I saw a video on the web that showed how to hook it to an ohm meter to test for resistance, it did have on spot that lost all connectivity... I'm guessing that might be the spot that I'm getting my hiccup. So got a new one at autozone, only thirty bucks and it'll be an easy fix... as soon as I get time... probably weekend. On a another note, did get the iac and vac lines cleaned/fixed the idle does seem better... I've only got one more hose that looks like it could need a changing... it looks about half inch and runs from the throttle body to the (I think) the evap system (on the firewall far drivers side), it says fuel on the line but I'm not sure, I think it runs from a blue nipple to the throttle... any idea what it is?

 

Sorry, this doesn't help answer your question as I'm not knowledgable with trannys either, but where did you find directions/video of how to test the TPS? I think mine might be causing problems, but I'd rather test it before I go buy a new one, just to make sure. If you could post the link with the info, that'd be great. Thanks

 

No Problem Podaso, YouTube - AUTO REPAIR: Throttle Position Sensor - Testing & Replacing (1 of 2)
In the video the guys removed the sensor to test it, I just pulled the connection off and did it on the engine. I also went to harbor freight and got some alligator clip extenstions for clipping to the ohm meter and to the sensor pins.. they were like 3 bucks. And then like in the video where they moved the sensor through the positions, I just grabbed the the trottle cable and moved it by hand... I just figured I didn't want to take the sensor off unless it was bad. Hope this helps.

 

Okay, cool. Yeah I should have thought before I posted that...I just searched it on youtube and watched the same video. Thanks a lot though for quickly posting the link. I'll check mine out in the next few days...if it ever stops raining here. Wish I had a garage.

Thanks again. Update us on how it goes with the tranny.

 

Not so fast. The ECM does NOT look at static resistance. It reads dc voltage. You have to backprobe the TPS with the connector installed at KOEO. Static resistance checks are feel good stuff, but don't mean much when the engine is running. Look for <1Vdc @ 0% and <5Vdc @ WOT. Monitor the sense wire using an acupuncture pin. The value should change in a linear fashion with no dropouts at any point along the entire sweep of the throttle blade.

 

Thanks for the Info... so does that mean that the guys in the video are incorrect? Or are you saying that if you check for resistance and it drops out it is bad (definately), and if it doesn't, it doesn't necessarily mean its good? I guess what I'm asking is, your test with dc voltage will tell you definately if it is good or bad. But if it comes up good on a resistance test, it doesn't definately mean it is good. When I tested my tps, (static resistance) it did travel in a linear fashion as I moved the throttle by hand, but it did drop out at maybe 1/4 throttle. I bought the new sensor (not installed yet), think I'll try to back probe the one on currently tomorrow.... I've never had any luck with back probing wires though. Also I'm guessing this is a two person job, one to probe and the other to work the throttle.
Eallanbogs.... I hope you don't think i'm second guessing you, I'm sure you know more about this than i do... but if you have a break at a certain point measuring resistance, wouldn't the dc current fall out at the same point because of lack of a connection? Just thinking out loud...Thanks again for the post.
Also, for the back probing... I don't have a set of probes or acupunture needles... does anyone know of anything else that works well... I'm just worried about damaging the wires.

 

I didn't watch the video. Of course a drop out could point to a problem. It's a potentiometer so you don't want any drop outs along the entire sweep. You can back probe using a paper clip. You want to grind a sharp point on one end. Be careful when piercing the insulation. You can also pull back the rubber seal on a waterproof connector to reveal the terminals inside of the connector. Attach the paperclip to your test lead using an aligator. You can buy more professional test equipment than a paperclip you have laying around, but if you only do this once in a while it will work. You can hold the test lead to the terminal with one hand and turn the throttleblade with the other while watching your meter. The other lead is on ground so you don't have to hold that one.

 

Mine cut out doing the simple test with the ohmmeter today...so I just went and spent the $30 for a new one...That was a lot easier than piercing the housing and trying to grind paperclips, etc. The job took 30 minutes total, including the trip to the Ford Dealership.

 

Podaso, did it make a difference?

 

It's OK to be a parts swapper if it works. Sometimes you get lucky, but most times you're throwing money away. Better to do a few tests to prove the part is defective and they pay for a new one.

 

I did the ohm test and it proved defective, just didn't feel the need to spend more time testing it...Yes it makes a huge difference. Before, when I would let off the gas, then push it hard again, it would increase RPMs about 1000 then fall off 500 before increasing again. I thought it was the tranny, but it proved to be the TPS. Acceleration is smooth now.